Rechargeable batteries are used in a variety of industrial and commercial applications such as fork lifts, golf carts, uninterruptible power supplies, pure electric vehicles and hybrid electric vehicles. Vehicular applications include applications related to propulsion as well as applications related to starting, lighting and ignition.
One aspect of battery operation that is particularly important for electric vehicle and hybrid vehicle applications is that of thermal management. In both electric and hybrid vehicle applications individual electrochemical cells are bundled together in close proximity. Many cells are both electrically and thermally coupled together. Therefore, the batteries used in these applications may generate significant heat during operation. Sources of heat may include, ambient heat and resistive or I2R heating on charge and discharge, where I represents the current flowing into or out of the battery and R is the resistance of the battery.
A battery generates Joule's heat and reaction heat due to electrode reaction at charging and discharging operations. A module battery may include a series of cells having a large capacity and a pack battery may include a series of the module batteries. Each of these may be configured to include several tens to several hundreds of cells arranged in series or parallel. The cells, with an increased electric capacity and sealed configuration, increase the amount of heat accumulated, with the result that heat dissipation out of the battery is retarded and the generated heat is accumulated within the battery. Consequently, the internal temperature of such a battery rises by a degree more than that of a smaller battery.
In vehicular applications, another aspect of battery operation is the maximization of packing density to provide maximum energy in relation to volume and weight. Typically, vehicular applications provide a minimal amount of space to incorporate a battery system.
Currently there exists a need in the art for a battery module housing and cooling system that provides stability for individual battery modules and thermal management of the system, to reduce, among other things, overheating of the system, deformation of the casings and shock to the system, while increasing packing density. Further, there exists a need in the art for a battery module housing and cooling system that maximizes the energy density of the battery modules and provides thermal management for the overall system.